sergeant



2 Sheets-*Sheet 1.

'Mllllllillll Patented Mar. 25, 1884.

El. A H

Kil

(No Model.)

H. C. SERGEANT.

ROCK DRILL.

-dotted line l 1, Figi.

llNsrTnn .STnTns PATENT @Trice-l HENRY C. SERGEANT, OF DENVER, COLORADO.

ROCK-DRILL.

SPECIFICATION forming part of Letters-Patent No. 295,682, dated March 25, 1884;.

Applicationiilcd December 4, 1853l lhaving supply-ports for admitting a motive agent to the cylinder on opposite sides of the piston, and an exhaust-port between the said supply-ports, and over which the piston passes u in its movements, of an automatic valve for controlling the admission of a motive agent to the said supply-ports, as hereinafter more fully described.

The invention also consists in a novel combination of parts, hereinafter particularly de# scribed, whereby the piston is cushioned at each end of its movement.

The invention also consistsV in a novel and simple combination of parts, whereby the rotation of the piston and drill-rod is elfected.

The invention also consists in the combination, with the piston-rod of a rock-drill, of a cylinder-head having in its bore or interior an annular groove for the reception of a packing and a tangential aperture or opening extending from the exterior of the head into said groove, and through which a packing may be introduced, as` hereinafter moreV fully described. l

' In the accompanying drawings, Figure l represents a partly sectional side `view of a rock-drill embodying my invention. Fig. 2 is a transverse'section on the dotted line a: fr, Fig. l, Fig. 3 is a similarsection in the dotted line yy, Eig. 1. Eig. 4 is a longitudinal section of the valve-seats, and a side view of the valve on a larger' scale. Fig. 5 is a transverse section of the valve on the dotted line z' z, Fig. 4. Fig. 6 is atrausverse section of the lower or front cylinder-head and piston-rod on the Fig. 7 is a plan ofthe drill complete.

Similar letters of reference designate corre- Y sponding parts in all the figures.

A designates the back ofthe drill, which is of ordinary constructiomand which issecured,

(No model.)

in the usual way, to a tripod or column (not here shown) -by a bolt, c.

B designates the cylinder, which is movable lengthwise of the back in ways or grooves b,

formed or provided inthe back A; and C designates the feed-screw, which is mounted in a bearing, b', Xed to the back A, and which may be turned by a handle, C'. screw engages with a nut, b2, secured in the cylinder B, and by turning the screw in one direction or the other the cylinder and all parts carried thereby are fed forward or moved back in a well-understood` manner.

D designates the piston, which is provided with any suitable ring-packing, and which, as here represented, is formed integral with the piston-rod D. This piston-rod D works through the lower or forward hea-d, B, of the cylinder B, and carries at its lower or forward end a drill-chuck, D, which may be secured upon the piston-rod D, or formed integral therewith. When the chuck and the piston are both formed integral with the rod D', I divide the forward head, B, axially or form it in two longitudinal halves, as best shown in Fig. 9the two halves or sections being securely held together by bolts c to form the head.

The feed- A ,'Ihe upper or back head, B2, ofthe cylinder Y consists ofa solid Vand lil-at piece or disk of metal, made slightly larger in diameter than the cylinder B, and `rabbeted at its periphery, l

so as to project slightly into the cylinder and to slightly overlap the end of the cylinder, as shown in Fig. l.

E designates a pieceof metal approximately annular in shape, and made entirely separate from and independent of `the head` B2, andformed with lugs or ears, through which are inserted bolts, c', whereby the piece E is immovably secured to the cylinder.

the feed-screw C, andas said piece is secured limmovably and rigidly to the end of the cyl- Ihe piece i E has a hole, c2, through it for the passage of E is bored out to the size of the head B2, and

has within it an elastic cushion, E', of rubber or analogous material, which is externally about as large as the head B2 and rests in contact therewith. This cushion is preferably annular, so that when compressed in a direc# IOO tion lengthwise of the cylinder it may crowd or expand inward. Y

F designates a follower, which is formed with an annular rabbet or shoulder, c3, and enters the bore of the piece E. .'Ihe head B and follower F are connected by bolts F', (best shown in Fig. 9,) and the cushion E serves -to l deaden a blow of the piston on either head Bl or B2. When the piston strikes the lower head B, the latter moves outward slightly and the follower F is moved inward, it being cushioned on E. When the piston strikes the head B2, the latter yields and moves outward slightly, it being cushioned on E'.

It will be observed that, inasmuch as the piece E is rigidly secured to the cylinder, it cannot yield, and said piece therefore forms a guide wherein the head B2 can move outward and the follower F can move inward, the cushion E being confined between the head and follower in the guidc'E.

The piston D is formed with or has secured to it an extension or head, D, which is of a size to work freely in the cylinder, and is somewhat longer than the length of pistonstroke. This head or piston-extension D3 is grooved spirally from end to end on its exterior, and the grooves are preferably ratchetshaped in cross-section, as shown in Fig. 2.

G designates a spring-actuated movable nutscction, which, as here shown, consists of a cylindric piece iitted in a socket or slideway, B3, which projects from the side of the cylinder, as shown in Figs. 2 and 9. The inner end of the nut G is concave, so as to approximate to the circumference of the piston-extension D, as shown in Fig. 2, and in the inner end or face of said nut-section are teeth which are adapted to engage with the spiral grooves of the piston-extension, as also shown in Fig. 2. It will be observed that the center ofthe nutsection Gis not radial to the piston-extension D, and that a line drawn through the center of said section would be tangential to a circle' smaller in diameter than the said piston-extension. This arrangement enables me to make the nutsection of sufficient size to engage with several ofthe spiral grooves and still have the faces of the teeth of the nutsectionv and the corresponding faces of the spiral grooves approximately radial to the piston-extension D. If such faces of the teeth and grooves were not radial orl approximately radial to the piston-extension D, a stronger spring would be required to prevent the nuts'ection being forced outward by the action of the piston-extension in its backward movement. The outer end ofthe socket B3 is closed by a plug, d, and between the inner end of tension D3; but when the nut-section is relieved of outward pressure the spring d will` return it into engagement `with the piston-extension D3.

On the nut-section G is a shoulder, di, which, by coming againstashoulder, d3, in the socket B, limits theinward movement of the said nut-section and forms a stop therefor. rIhe length of the nut section G inward of the shoulder dAz is such that when the nut-section is in its inward position its inner end will not press upon the piston-extension and tend to` force the latter against the opposite side of the cylinder, although the teeth of the nutseetion will be in strong engagement with the' spiral grooves. In Fig. 2 it will be seen that the shoulder cl2 is against the shoulder d3, and yet the surfaces of the teeth of the nut-section are out of contact with the surfaces of the grooves of the piston-extension D3, although the said teeth extend into and are in engage ment with said grooves. v

Although I consider the stop for preventing the nut-section G from pressing against the piston-extension D3 as very desirable, still it is not indispensable, and the nut-section might be made in the form of a straight cylinder destitute of a shorlder. The cylinder is provided with supply-ports ee', and the steam or other motive agent enters the cylinder through the port eto produce the forward working-stroke of the piston D. Between the piston D and the piston head or extension D3 is an annular groove or recess, ef, which permits the steam to pass from the port e entirely around the piston, and enables the steam to pass freely through all the grooves of the piston-extension D3 to the back end thereof'. Before the piston commences its forward or working stroke the steam, acting upon the inner end of the nut-section G. forces the latter back IOC or outward into its socket B3, and entirely I steam-pressure behind it, the nut-section G being held out of engagement with the grooves of the piston-extension D;I during its whole forward movement. As soon as the pressurel behind the piston is relieved by the opening of the exhaust, and before the piston commences its backward movement, the nut-section G is forced inward by the spring d', so that its teeth enter the spiral .grooves of the piston-extension D3, and during the backward movement of the piston the piston-rod and piston are turned by the engagement of the spiral grooves of the piston-extension with the nutsection G. During the whole backward movement of the piston the nut-section is supported by the shoulders cl2 d3, andhence the said nutsection does not force the piston extension its outward movement by pressure behind it, or retarded in its inward' movement by the formation of apartial vacuum behind it. The plug d might be imperforate; but the nut-section would then be less activein its movements, and a stronger spring, d', would be` necessary. When the nut-section G is forced .outward, its outer end closes against the plug (Z and prevents the escape of steam through the aperture' d4. `Not only does the nut-section G, operating as described, form a more simple and effective rotating device t-han any heretofore used, but the forcing back and holding of the nut-section Gout of all contact with the piston-extension D3 during the working stroke frees `the piston entirely from all connection with the rotating device and enables it to be operated with less friction. The piston may be readily turned by hand in the direction of the arrow shown in Fig. 2, as the nut-section G will yield readily when the inclined faces of the grooves on the piston-extension D3 act upon the inclined faces of its teeth.

B4' designates the valvechest, to which steam or other motive agent is admitted by the pipe j', and H designates the valve whereby the admission of steam to the ports c e is controlled. |The steam from the pipe f enters an annular belt or recess, f', in the valve-chest, and thence passes, under control of the valve H, to the port e or the port e. rlhe valve His made in the form of a double puppet `valve, and is adapted to close upon either ofthe seats c2 e3, between which it works. The valve has but a slight movement, and, as shown in Figs. l and et, has `just moved to the left to ,close `on the seat e and Vopen the` seat e3 to admit steam to t-he port e; but the piston has not yet commenced its forward movement, it being in its rearmost position. The position ofthe valve is the same in Figs. 1 and 4. The seats e2 e3, as here shown, are formed on the adjacent ends of tubular pieces H H2. (Best shown in Fig. 4.) These are both inserted into the valvechest B* from one end thereof, and the end is then closed by a plug, f2. The end of, the piece H bears against a shoulder, j'-and a shoulder on the exterior of the piece H2 bears against a shoulder, f, in the valve-chest. The distance apart of the seats e2 e3 is thus determined. The valve H has arms or websf,

projecting from opposite sides` into the seatpieoes H H2, and serving t'o properly guide the valve without materially interfering with the free passage of steam through `the seats," and at the outer ends of these webs or arms f 5, I have shown small disks f against which the steam strikes or impinges as it passes to the onenside or theV other.

The cylinder is provided between the two supply-ports e e with an annular exhaust belt and port, g g, from which extends an exhaustpipe, g2. (Shown in Figs. 3 and 9.) This exhaust is unprovided with any valve, and is always open to the atmosphere, except while the annular port g is covered by the piston in its movements.

VThe operation of the valve H is as follows:

" As before stated, the valve H has just moved not yet moved. At this time the cylinder IBl forward of orto the left of the piston D is open to the atmosphere through the exhaustport g and belt g. Consequently there is but a very slight pressure on the. left side of the valve H, and said valve is held strongly against the seat e'l by the pressure of steam on its right side. The steam, rushing to the right through the seat e and striking against the disk f6, has a tendency to draw the valve away from the seat e?, but cannot do so while the exhaust from the cylinder is open to the atmosphere. The piston D isnow forced forward under full pressure of steam; but as soon asit covers the exhaust-port g the low steam remaining in the forward end of the cylinder is trapped and compressed to such an extent as to create a pressure on the left side of the valve H. rlhe pressure thus created is not nearly so great as the pressure on the right side of the valve; but it relieves the valve to such an extent that the drawing force produced by the steam striking on the disk f6 is sufficient to move the valve to the right and open the seat t2. The valve H is thus moved to the right and Steam admitted through the seat e2 just before the piston completes its stroke; but the momentum, aided by pressure on the backof the piston, causes the drill to strike with full force, and steam acts on the piston to make the return-stroke. The piston, in its forward stroke, having passed beyond the exhaust-port g', there is a free exhaust from the right hand of the piston D during its return-stroke until it covers and passes yhe exhaust-port g; but as soon as this occurs the steam is trapped on theright-hand side, or back of the piston, and compressed untilit relieves the valve H sufficiently to allow it to be drawn to the left by theaction of the steam, whereupon the operation is repeated. At each stroke of the piston the valve moves before IOO IIO

the completion of mov ement ofthe piston, and

therefore there is no liability of the piston strikingviolently against the heads of the cylinder. l i

In order to pack` the piston-rod D in the groove, as best shown in the transverse section, Fig. 6. The outer end of the tangential aperture h is closed by a plug, h2, and when said plug is removed a strip or piece of dexiblepacking, h3, inserted through the aperture 7L,will follow the groove lnand on being forced in will be compacted tightly in the groove and round the rod D. The strip or packing may with a punch, and Whenever the packing becomes worn and there is any leakage around the rod the plug h2 is removed and additional pieces of packing are driven in until the packing is tight. Y T

Vhead B', I form in the head an annular groove, n h, and a hole or aperture, 7L', tangential to said be forced or driven in through the aperture h When the head B is divided,'as here shown, the parts may be separated to permit of the worn-out and worthless packing being re moved from the groove h; but such clearing out of the groove is not necessary, :1s-packing may be driven in from time to time to maintain a tight joint around the rod D.

The drill-rod I is tted in a socket in the chuck D2, and is clamped therein by means of two bolts, I, the heads fi of which are adapted to fit the drill-rod, and are caused to clamp it tightly by screwing up their nuts i2; but as this chuck is the subject of another applicationfor patent led by me on the 23d day of February, 1884, No. 121,670, and is nota part ofthe invention herein claimed, it needs no further description here.

Although I have herein frequently referred to steam as the motive agent employed, the invention is applicable to drills operated by compressed air or steam.

Vhat I claim as my invention, and desire to secure by Letters Patent, is

1. In a rock-drill in which the exhaust-port is controlled by the piston, the combination ot' the ported cylinder and the piston with a iluidcontrolling valve actuated by the inliowing fluid when the compression is made on the exhaust end of the cylinder, substantially as shown and described.

2. The combination, with the cylinder B, having supply-ports e c and an exhaust-port, g, between said supply-ports, of the piston D, having a movement across and considerably beyond the said exhaust-port at each stroke, and the automatic valve H, movable between the valve-seats e2 c3, for controlling` the admission of a motive agent to said supplylports e e', substantially as described.

3. The combination, with the cylinder B, having supply-ports c e and an exhaust-port, g', between said supply-ports, of the piston D, having a movement across and considerably beyond the said exhaust-port at each stroke, and the automatic valve H, movable between the valve-seats e2 e, and provided with the disks f6, upon which the motive agent acts to move the valve, substantially as herein de scribed.

4. The combination of the cylinder B, the

head B', the follower F, and bolts F, connect-i the spiral grooves of the piston head or eXtension, and capable of being forced back by the act-ion of the motive agent upon its face or inner end to free it entirely from the spiral grooves of said piston head or extension, substantially as and for the purpose herein described.

6. The combination, with the cylinder of a rock-drill, of a piston head or extension having a spirally-grooved exterior, a spring-actuated nut-section engaging with the spiral grooves of said head or extension, and capable of being forced back by the pressure of the motive agent upon its face to free it entirely from said spiral grooves, and a stop for limiting the inward movement of said nut-section, substantially as and for the purpose herein described.

7. The combination of the cylinder B, having the transverse socket or slideway B3, provided with the shoulder d3,the spirally-grooved piston-extension D3, the movable nut-section G, engaging with the grooves of said pistoneXtension, and provided with the shoulder d2, the spring d', and the plug` d, closing the outer end of said socket or slideway B3, substantially as herein described.

8. The combination, with the piston-rod D', of the longitudinally-divided cylinder-head B', having the annular packing-groove h and the tangential aperture h', substantially as herein described.

HENRY G. SERGEANT.

Witnesses:

FREDK. HAYNns, En.v L. lVIoRAN. 

